Sill plate and method of use

ABSTRACT

The present invention provides a sill plate for use between a foundation and a frame of a structure for attaching the frame to the foundation. The sill plate includes an elongated sill board and a compressible seal member attached to a side of the sill board, the seal member for placement adjacent the building foundation for sealing the joint between the foundation and the sill plate. In a preferred embodiment, the sill board is formed of a composite material including wood or reclaimed wood. Additionally, the present invention provides a method of installing a sill plate on the foundation of a building.

FIELD OF THE INVENTION

The present invention generally relates to a sill plate for use in theconstruction industry, and more particularly to a sill plate including acomposite sill board and a seal member attached to the sill board foruse between a building foundation and a frame of the structure andmethod of use of the same.

BACKGROUND OF THE INVENTION

In the construction of new structures such as single and multiple familydwellings, condominiums, and light commercial buildings, local andnational building codes usually require the installation of two sillmembers between the concrete foundation and framing of the structuresecuring the framing to the foundation and for providing a sealtherebetween. The first or bottom most sill member is typically apolyethylene foam membrane which is installed on the concrete foundationover anchors secured to the concrete. The second sill member is a sillplate usually formed of pressure treated lumber (e.g., 2″×6″ pressuretreated boards) installed over the foam membrane and secured to thefoundation using the anchors. The foam membrane acts as a sealantbetween the poured concrete or concrete block foundation and thepressure treated sill plate. Typically, the framing for the structure isinstalled on top of the sill plate and secured to the sill plate andfoundation via the anchors.

The foam membrane often includes an adhesive for attaching the foammembrane to the concrete foundation. Usually the adhesive is protectedwith an additional cover layer designed to be removed during aninstallation process.

While the above-identified prior art sill members and sill plates arewidely used and meet national and local codes, serious problemsassociated with this type of sill members still exist, some of which canlead to a failure of the sill plates. Failure of a sill plate couldcompromise the structural integrity of an entire building. Common causesof failure associated with the above-described prior art sill platesinclude termite damage, rot due to high moisture, and damage caused byboring insects including carpenter ants. Additionally, pressure treatedlumber may not be properly treated thoughout the entire board which maycause the board to rot prematurely and lead to failure of the board.

The risk of sill plate failures has become even greater with the recentchanges in treatment methods and the chemicals used as preservatives totreat pressure treated lumber. The Environmental Protection Agency hasbanned chromated copper arsenate (CCA) as a preservative for woodintended for residential use. Accordingly, in an effort to makealternative preservatives effective, the copper content in thepreservatives has been increased substantially. One disadvantage ofincreasing the copper content in treated lumber is that thecorrosiveness of the lumber is also increased. According to the AmericanWood Preservers Association, typical pressure treated lumber currentlyavailable in the marketplace is approximately five times more corrosivethan previously used lumber treated with CCA.

The corrosive effects of the new treatment processes for pressuretreated lumber present a serious problem for the construction industrywith respect to sill plates and the anchor bolts used therewith. Forexample, anchor bolts in contact with the treated lumber are susceptibleto corrosion and can fail as a result thereof. The corrosion offoundation anchor bolts will certainly compromise the structuralintegrity of homes in high wind areas of the country and dramaticallyincrease devastation in areas of the country affected by hurricanes andtornados. For slab on grade construction, the problem is increased, asfoundation anchor bolts are more likely to be exposed to moisture whichcan increase the risk and/or rate of corrosion of steel bolts.

Another disadvantage associated with the above-described prior art sillmembers is that the foam membrane and pressure treated lumber areseparate products which require a multiple-step installation processincluding, removal and disposal of an adhesive covering material fromthe foam membrane; installing the foam membrane and adhering the same tothe foundation; and installing the sill plate on top of the foammembrane. As mentioned above, the foam membrane often includes acovering material over an adhesive which must be removed prior toinstalling the foam membrane on the foundation. In cold weather, theadhesive may not seal properly to the foundation such that the alignmentbetween the foam and the sill plate or the foundation could becompromised. Alternatively, if the foam membrane is installed withoutremoving the adhesive covering material, the joint between thefoundation and the foam membrane may be unsatisfactory as the foammembrane will not properly engage the concrete foundation with theadhesive covering therebetween.

Further, the two separate products (foam membrane and pressure treatedsill plate) are typically handled separately from ordering the materialsthrough the installation thereof, which adds to the cost of thestructure and increases the risk of error during an installationprocess. For example, if the foam membrane is not present on a job-site,the sill plate may be installed without the foam membrane which couldresult in an unsealed joint between the sill plate and the foundation.Further, because the foam membrane and sill plate are installedseparately, each piece must be separately aligned with the foundationduring the installation process.

Based on the foregoing, it is the general object of the presentinvention to provide a sill plate and method of use that improves upon,or overcomes the problems and drawbacks associated with prior art sillplates.

SUMMARY OF THE INVENTION

The present invention provides a sill plate for use between a foundationand a frame of a structure which includes an elongated sill board, and acompressible seal member attached to a side of the sill board. The sealmember is preferably a foam membrane configured for placement adjacentthe foundation for sealing the joint between the foundation and the sillboard.

In another aspect, the present invention provides a method of installinga sill plate on a foundation for providing a sealed joint between thesill plate and the foundation.

Preferably, the sill board of the present invention is manufactured froma composite material that is weather resistant and will not rot orsplinter and is not susceptible to damage from insects. In one preferredembodiment, the sill board is an extrusion formed of a compositematerial including wood flour, polyethylene and other processingadditives. The composite material also preferably includes antifungaland antiparasite agents and does not contain any toxic chemicals orpreservatives.

In one embodiment, the sill board is approximately 5/4 inches thick andapproximately six inches wide and is available in various lengthsincluding twelve, sixteen and twenty feet long.

The seal member is attached to a side of the sill board for engagementwith a foundation for sealing the joint between the sill board and thefoundation. In a preferred embodiment the seal member is a compressiblepolyethylene foam membrane approximately ¼ inches thick andapproximately six inches wide adhered to a side of the sill board. Theadhesive is preferably a polyethylene adhesive such as that typicallyused in the construction industry.

Openings, such as holes are typically bored through the sill plateincluding both the sill board and the seal member for receiving afastener for attaching the sill plate to a foundation.

One advantage of the present invention sill plate is that the compositematerial of the sill board is not corrosive and will not cause damage toanchor bolts or other fasteners used therewith. Accordingly, structuresattached to sill plates of the present invention are less susceptible todamage caused by sill plate failures than those built on sill plates ofthe prior art.

Another advantage of the present invention sill plate is that the sillboard and seal membrane attached thereto is a one piece assembly thatinstalls on a foundation in one step which reduces the cost ofinstallation when compared to prior art sill plates and the foammembranes used therewith.

Another advantage of the present invention is that the sill plate doesnot require any adhesives for the installation thereof, thus even incold or wet weather, the sill plate can be installed and provide aweather-tight seal between a foundation and the sill plate.

A further advantage of the present invention is that the sill board andseal member are pre-aligned such that there is no need to separatelyalign the seal member with the foundation during an installationprocess. Accordingly, there is no risk of the seal member folding orslipping during an installation process which can occur with prior artsill plates.

Other objects and advantages of the present invention will becomeapparent to those skilled in the art upon consideration of the followingdescription of embodiments of the invention and the attached figures.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a perspective view of one embodiment of a sill plate inaccordance with the present invention shown mounted to a concretefoundation.

FIG. 2 is a perspective view of a sill plate in accordance with thepresent invention.

FIG. 3 is an end view of the sill plate of FIG. 2.

FIG. 4 is a partial top view of the sill plate of FIG. 2.

DETAILED DESCRIPTION OF THE INVENTION

As shown in FIGS. 1-4, an embodiment of a sill plate in accordance withthe present invention is generally referred to by the reference numeral10. The sill plate 10 includes a generally rectangular sill board 12having first and second opposing sides 14 and 16 respectively, opposingedges 13, and opposing ends 15 and 17. A seal member 18 is attached tothe second side 16 of the sill board 12 and aligned therewith.

Preferably the sill board 12 and the seal member 18 are of substantiallythe same width W and aligned width-wise one with the other along alength L of the sill board 12. The sill board 12 and seal member 18cooperate to define a plurality of holes or openings 20 which extendthrough both the sill board and the seal member for attaching the sillplate 10 to a foundation 22. (See FIG. 1). Typically, the openings 20are holes bored through the attached sill board 12 and seal member 18 inthe field.

Referring again to FIG. 1, a plurality of anchor bolts 24 are typicallysecured to the foundation 22 and extend outwardly from a top side 26thereof. Normally, as used with concrete foundations, the anchor bolts24 are placed in the foundation 22 prior to the concrete being fullycured and are secured thereto once the concrete cures around the anchorbolts. An end portion 28 of the anchor bolts 24 is usually threaded forreceiving a nut (not shown) and securing the sill plate 10 and/or aframe member (also not shown) to the foundation 22.

Typically, the openings 20 (See FIG. 1) are circular holes bored throughboth of the attached sill board 12 and seal member 18 in the field.Normally, the openings 20 define a diameter larger than the diameter ofthe anchor bolts 24 such that the position of the sill plate 10 can beadjusted slightly relative to the foundation 22 and/or adjacent sillplates.

The sill board 12 is preferably made from an extruded wood thermoplasticcomposite lumber (WTCL) product which includes wood flour, high densitypolyethylene as well as other processing additives. The composite lumbermaterial also preferably includes one or more antifungal andantiparasite agents. In one preferred embodiment, the sill board 12includes a minimum of about 50 percent wood flour by weight and amaximum of about 50 percent high density polyethylene and processingadditives by weight. When subjected to tests involving weathering,insect attacks, and other decaying elements, the above-describedpreferred WTCL composite material of the sill board 12 meets or exceedsthe durability and performance of both preservative-treated or naturallydurable lumber. The above-described WTCL sill board 12 has beenevaluated and shown satisfactory performance for use within atemperature range of about negative 20 degrees Fahrenheit to about 125degrees Fahrenheit. Although, the preferred embodiment of the sill board12 is a composite material including wood flour and polyethylene, thescope of the invention is not limited in this regard as other compositematerials which include wood, reclaimed wood, plastic, polymers, cementor other wood substitutes can also be utilized and are within the scopeof the invention.

Referring to FIGS. 2-4, the seal member 18 is preferably a flexible foamgasket fully adhered to the side 16 of the sill board 12 via an adhesivelayer 19. The adhesive layer 19 is a polyethylene construction adhesive,however other types of adhesives could be utilized without departingfrom the scope of the invention. Alternatively, the seal member 18 canbe secured to the sill board 12 with other types of fasteners such asstaples.

In a preferred embodiment, the seal member 18 is a compressiblepolyethylene foam strip approximately one-quarter inch thick and sixinches wide for use between the sill board 12 and the foundation 22 toreduce air infiltration between the foundation and the sill board. Theseal member 18 is a preferably a closed-cell polyethylene foam whichprovides a durable seal even when exposed to water and/or water vapor.Although the seal member 18 is foam, other compressible materials canalso be utilized for the seal member without departing from the scope ofthe invention.

Referring to FIG. 2, the seal member 18 includes an end portion 21 whichextends beyond the end 15 of the sill board 12 a distance identified bythe letter X which in the illustrated embodiment is approximately equalto the width W of the sill board. At the opposing end 17, the sill board12 extends beyond the end of the seal member 18 a distance X also equalto about the width W of the sill board. The end portion 21 provides anoverlapping seal at the joints at the corners of a foundation 22 orbetween sill plates 10 arranged end to end along a wall of thefoundation forming a ship lap type joint between the seal member 18 andand an adjacent sill board 12. The overlapping seal formed by the endportion 21 helps to ensure a proper seal at the joints between adjacentsill boards 12. If the end portion 21 of the seal member 18 is notuseful in a particular application, such as at the corner of afoundation, the end portion can easily be removed by cutting thematerial of the seal member flush with the end 15 of the sill board 12using an ordinary utility knife or another cutting tool.

In another embodiment of the present invention sill plate 10, the sealmember 18 can be approximately the same length L as the sill board 12wherein the end portion 21 is not provided. Alternatively, the sealmember 18 can be configured to include an end portion 21 extendingbeyond the length one end 15 of the sill board 12 and end flush with theopposing end 17 thereof.

The sill plate 10 is preferably a pre-fabricated assembly including thesill board 12 and the seal member 18 adhered thereto. Preferably, theseal member 18 is adhered to the sill board by applying a layer of anadhesive 19, such as a settable polyethylene adhesive, to one or both ofthe surfaces 16 of the sill board and a surface of the seal member,joining the two surfaces together, and allowing the adhesive to set.Additionally, a roller or compression device can be used to attach theadhesive to the mating surfaces and ensure adhesion therebetween.

In use, the sill plate 10 of the present invention can be installed inone step on the top surface 26 of a foundation 22. Typically, prior toinstalling the sill plate 10, any dirt and loose debris is removed fromthe top surface 26 of the foundation 22. Next, the sill plate 10 isaligned with the foundation, the location of the anchor bolts 24 markedon the sill plate, and the openings 20 (i.e., holes) are drilled throughthe sill plate. One method of marking the sill plate 10 for drilling theopenings 20 therethrough includes positioning the sill plate 10 on topof the anchor bots 24 with the surface 14 of the sill board resting onthe anchor bolts and aligning the sill plated with the foundation. Bystriking the bottom of the sill plate over top of the anchor bolts witha hammer, the anchor bolts will mark the surface 14 of the sill board 12thereby marking the location for the openings 20 to be drilled throughthe sill plate 10.

To install the sill plate 10 on the foundation 22, the sill plate ispositioned on the top surface 26 of the foundation 22 with the sealmember 18 facing the foundation and the anchors 24 extending through theopenings 20 in the sill plate. If the openings 20 allow for adjustmentof the position of the sill plate 10 relative to the foundation 22, theposition of the sill plate can then be adjusted relative to thefoundation as necessary which completes the installation process.

Typically, following the installation of a frame member on top of thesill plate 10, nuts are secured to the anchor bolts 24 which draw theframe member (not shown) and the sill plate 10 towards the foundation 22thereby securing the same thereto. Tightening the nuts on the anchorbolts 24 causing the frame member and sill plate to be drawn towards thetop surface 26 of the foundation also compresses the seal member 18thereby forming a weather-tight seal between the foundation and the sillplate 10.

The installation of the sill plate 10 does not require aligning the sillboard 12 with the seal member 18 as the sill plate is provided with theseal member attached to the sill board. Further, there is no adhesiverequired to install the sill plate 10 as the present invention does notrequire an adhesive between the foundation 22 and the seal member 18.Since installation of the sill plate 10 does not require any adhesives,the sill plate can be efficiently installed in any weather conditionsincluding cold and wet weather and provide a sealed and weather-tightjoint between a foundation and the sill plate.

The foregoing description of embodiments of the invention has beenpresented for the purpose of illustration and description, it is notintended to be exhaustive or to limit the invention to the formdisclosed. Obvious modifications and variations are possible in light ofthe above disclosure. The embodiments described were chosen to bestillustrate the principals of the invention and practical applicationsthereof to enable one of ordinary skill in the art to utilize theinvention in various embodiments and with various modifications assuited to the particular use contemplated. It is intended that the scopeof the invention be defined by the claims appended hereto.

1. A sill plate for use between a foundation and a frame of a structure,the sill plate comprising: an elongated sill board having two opposingsides, and a compressible seal member attached to one of the two sidesof said sill board, said seal member for placement adjacent thefoundation for sealing the joint between the foundation and said sillboard.
 2. The sill plate according to claim 1 wherein said sill boardcomprises a composite material.
 3. The sill plate according to claim 1wherein said seal member is attached to said sill board with anadhesive.
 4. The sill plate according to claim 1 wherein said sill boardand said seal member define at least one opening through both said sillboard and said seal member for receiving a fastener for attaching saidsill plate to said foundation.
 5. The sill plate according to claim 1wherein said seal member extends beyond an end of said sill board. 6.The sill plate according to claim 2 wherein said composite materialincludes wood flour.
 7. The sill plate according to claim 2 wherein saidcomposite material includes wood or reclaimed wood.
 8. The sill plateaccording to claim 2 wherein said composite material includes a polymer.9. The sill plate according to claim 1 wherein said seal member includesa foam membrane.
 10. A sill plate for use between a foundation and aframe of a structure, the sill plate comprising: an elongated sill boardformed of a composite material, and a compressible seal member adheredto a side of said sill board, said seal member for placement adjacentthe foundation for sealing the joint between the foundation and saidsill board.
 11. The sill plate according to claim 10 wherein saidcomposite material includes a minimum of about 50% wood flour by weight.12. The sill plate according to claim 10 wherein said composite materialincludes a maximum of about 50% polyethylene by weight.
 13. The sillplate according to claim 10 wherein said seal member includes a foammembrane.
 14. The sill plate according to claim 10 wherein the sealmember extends beyond the end of the sill board at one end of the sillboard and the sill board extends beyond the seal member at the other endof the sill board.
 15. A method of installing a sill plate on afoundation of a building, the method comprising the steps of: attachinga seal member to a sill board forming a sill plate, and thereaftermounting said sill plate on a top surface of a foundation such that saidseal member engages a top surface of the foundation for sealing thejoint between said sill plate and the foundation.
 16. The method ofinstalling a sill plate in accordance with claim 15 wherein the step ofmounting includes compressing the seal member between said sill plateand the foundation.
 17. The method of installing a sill plate inaccordance with claim 15 wherein the step of attaching includes adheringsaid seal member to said sill board.
 18. The method of installing a sillplate in accordance with claim 15 further comprising a step of defininga plurality of openings in said sill plate for attaching said sill plateto said foundation.
 19. The method of installing a sill plate inaccordance with claim 15 wherein the step of attaching further comprisesextending said seal member beyond at least one end of said sill boardsuch that said seal member is longer than said sill board and extendsbeyond the length thereof.
 20. The method of claim 17 wherein the stepof adhering includes using a settable adhesive and allowing the adhesiveto set prior to installing the sill plate.